Q&A with Brookfield

Get Answers to Your Texture Questions

What's your texture challenge?


Customer Challenge: There are several types of probe to choose from when setting up a test: cylinder, ball, cone, blade, etc. How do I determine which is best for evaluating my material?

BROOKFIELD ANSWERS: Experimentation is the best approach for determining which probe gives repeatable data that correlates with acceptable product quality. Published literature on QC test methods will oftentimes suggest a probe that has proven its usefulness and become a standard choice, such as AACC36 for testing sliced bread (American Assoc of Cereal Chemists). Shape of probe may have relevance, such as ball probe for penetrating soft solid materials like mayonnaise; product underneath the ball flows up and around the curved surface as the probe penetrates downward, giving a constant force signal which correlates with stiffness of the mayo.


Customer Challenge: Our company manufactures chocolate candies. Some have centers filled with different ingredients, such as flavored creams, coconut, nuts, etc. Others have a hard candy shell coating the exterior. What is the correct way to verify the textural quality of the chocolate candy? Some customer complaints focus on the center filling not always having the same feel when biting into the chocolate, others describe the outer candy coating as "too hard".

BROOKFIELD ANSWERS: The Brookfield CT3 Texture Analyzer with various cylinder probes provides the needed test capability for Quality Control to verify that chocolate candies will have a consistent mouth feel. Small diameter cylinders referred to as “punch probes” perform penetration tests on candy coated chocolates and quantify the force needed to crack the hard shell that envelops the chocolate. R&D will specify maximum allowable force value which equates with the biting force used by the consumer when eating candy-coated chocolates. Large diameter cylinders referred to as “compression discs” perform crush tests on chocolates and simulate the action of molar teeth when chewing a chocolate candy. R&D will specify a maximum allowable force for this test as well to ensure that customer satisfaction is achieved.

The tests are easy to set up and quick to execute, typically taking no more than a minute. The probe attaches to the CT3 Texture Analyzer. The operator selects the probe speed and penetration or compression distance into the chocolate. The instrument displays the peak force recorded during the test. An added benefit is the automatic calculation for amount of work to penetrate/compress the chocolate which is also displayed. This value gives a measurement of the consumer’s effort to accomplish the biting or chewing action.


Customer Challenge: Occasionally my CT3 Texture Analyser appears to start collecting data before it has reached the test sample surface. Why is this?

BROOKFIELD ANSWERS: The “trigger point” is by definition the amount of load in grams or Newtons that the probe detects before the texture analyzer starts to record the test data. The instrument operator inputs this value into the method prior to the test. This value may be set to zero in which case the CT3 is instructed to collect data as soon as the test is started. A table recommending a minimum trigger point value for each load cell appears below.

However, even when the trigger point has a non-zero value, you may experience early data collection for one of the following reasons:

  1. The trigger force is set lower than the recommended value for the load cell.
  2. An open window, door or circulating fan is located near to the texture analyser and has caused a premature trigger to occur.
  3. Vibration on the table on which the texture analyser is situated which may come from other sources


Customer Challenge: The test does not start when the probe reaches the product. What is wrong?

BROOKFIELD ANSWERS: The trigger force may be too high for this particular sample and should therefore be lowered.


Customer Challenge: How many samples should I test when attempting to establish a method

BROOKFIELD ANSWERS: Time and sample availability are often limiting factors. It is necessary to test at least 3 samples to see if there are any noticeable differences. If possible, testing 4 or more samples allows you the opportunity to differentiate between samples with some confidence. For best practice, it is recommended that 5 or more samples are tested.

Note: It is not statistically valid to apply a standard deviation to a sample set fewer than 4 and ideally these statistical measures should be applied to a sample set of 5 and above.


Customer Challenge: How should I test the texture of ground beef? There is some variability in the quality of the beef that we process. In addition, we would like to have a consistent method that compares the raw beef to the finished product, such as hamburger patties, both cooked and uncooked.

BROOKFIELD ANSWERS: Both the sample preparation and the test method are equally important. Use the same size container for each test on the raw ground beef. Do not compress the beef; put it into the container in a loosely consolidated condition. The diameter of the container should be much larger than the probe that is used to test the beef. Depth of beef in the container should be 4 inches or greater.

Instrument choice will be the CT3 with 10kg load cell or higher.

Probe choice should be either spherical or shallow-angle cone. Examples include the TA43 2.54cm-diameter ball probe or the TA54 shallow-angle 170 degree 40mm-diameter cone probe). If you already have the Brookfield standard probe kit, you may try the TA2/1000 60 degree 30mm cone probe as an alternative.

Test method is Distance Test with penetration to a depth of 10mm at speed of 1 or 2mm/sec. As the probe descends into the ground beef, material around the edge of the probe will push off to the side. Record the peak load to measure the firmness of the ground beef and the adhesive force during retraction of probe which may correlate with the cohesiveness of the ground beef.

Use the same type of test method for the uncooked and cooked hamburger patty. Set the target value for the Distance Test to half the thickness of the patty. Test speed is either 0.5 or 1.0mm/sec, whichever gives more consistent data.

Contact Brookfield's product manager for Texture Products if further assistance is required on measurement methods for ground beef.


Customer Challenge: Is there an established method for measuring the texture of bread?

BROOKFIELD ANSWERS: The baking industry recommends a two-cycle test known as Texture Profile Analysis to evaluate important physical characteristics of bread such as firmness, springiness, and chewiness. TPA utilizes a standard cylinder probe to press into a slice or two of bread at a defined rate of penetration. The Texture Analyzer measures the resistance to penetration and records the result in grams (Newtons) of force. The probe repeats the same procedure a second time while detecting how much distance the bread has recovered from the first compression cycle. This method allows provides the raw data from which calculations for springiness and chewiness are derived. The mathematical equations for these parameters appear in the 2015 Brookfield Catalog on page 56.

This method is customarily used to test fresh bread as well as bread that has been on shelf for a period of time. The objective is to determine how rapidly it loses the “freshness” quality that it possesses immediately after baking.


CUSTOMER CHALLENGE: Recent QC tests using the ball probe with our Texture Analyzer to measure the consistency of our yogurt product seem high. And we have also received a few customer complaints about our product being "thicker". We expect to measure a peak load of not more than 2000 grams when pushing into the filled cup at 2 mm/sec. We are consistently recording values above 2500 grams. We are not sure whether our product is changing or the instrument is out of calibration. How do we check the Texture Analyzer for proper calibration?

BROOKFIELD ANSWERS:Run a calibration check on your Texture Analyzer with the calibrated weight set. The load cell in your instrument is rated at 4500 grams. The corresponding weight set, Part Number TA-CW-4500C, comes with individual weights that add up to 4500 grams. This provides the ability to check the linearity of the load cell in your instrument. Readingsfor any combination of weights that you attach to the probe coupling must come within 0.5% for the calibration check to pass. In your case check the load cell at 2000 and 2500 grams. The allowable deviation must be less than 10 and 12.5 grams respectively. In addition, you should check the load cell up to its maximum rated capacity, namely 4500 grams.

If the readings are too high, return your Texture Analyzer to the nearest authorized Brookfield Service Center. You can get a loan instrument if needed while yours is being serviced. The turnaround time is only a few days and the cost is small compared to the problems that might be caused by shipping product that is out of specification. You will also receive a new Certificate of Calibration for your Texture Analyzer.

Submitted by: Anonymous


CUSTOMER CHALLENGE: What are the choices for types of probes that can be used to make a texture measurement on foods? How do you know which type of probe to choose? Do I need to use a special container for the test sample?

BROOKFIELD ANSWERS: Texture probes have four basic shapes: cylinder, cone, ball, and blade. Choose the probe that simulates the action which you want to duplicate. Dipping a spoon into a cup of yogurt can be replicated with either the cylinder or ball probe. Biting into a candy bar suggests use of either blade or cone probe. Cutting into a piece of meat or fish is typically accomplished with a blade probe.

The test sample container can be the actual package which the consumer buys on shelf. For example, test store-bought yogurt and puddings directly in the cup used to package the product. The same advice applies to creams and dips. If refrigeration is recommended by the manufacturer prior to serving the food product, then condition the item to 4°C prior to testing.

If not sure what probe may work best, purchase the General Probe Kit which has each of the four basic types in various sizes/dimensions. This provides the flexibility that you may require as you test different food products and establish the test method that works best for each item.

Submitted by: Anonymous


CUSTOMER CHALLENGE: Medicinal and pharmaceutical products that are applied by spraying have gained in popularity because they easily coat the targeted surface without need for further spreading action by the consumer. Oral and nasal sprays are good examples; they work with great rapidity, migrating quickly to the target area and producing a very desirable benefit for the patient in terms of fast relief. How do we, as a manufacturer, know whether the spray will actually stick to the targeted surface once it arrives? Relying on feedback from user groups is one way to get the necessary information, but has a highly variable range of responses, since it is based on human judgment, and can be quite expensive. Is there a way to do this type of assessment using instrumentation?

BROOKFIELD ANSWERS: Instruments known as Texture Analyzers or Texture Testers provide a convenient and objective means for making this measurement. These devices can run a compression test within a matter of seconds to determine the "stickiness" of sprays applies to a surface. A probe, shaped like a cylinder, presses down on a sample of the material with a defined force, then pulls back while measuring the resistance to separate away from the material. The Texture Tester gives objective results compared to the human sensory panel. Texture Testers are easily affordable, simple to operate, and allow test technicians to make measurements within a matter of minutes when first using the instrument.

Submitted by: Anonymous


CUSTOMER CHALLENGE: We are trying to measure the consistency of our salad dressings, which range from the consistency of mayonnaise to thick and creamy blue cheese dressings. We use different T-bar spindles with the Helipath Stand on a rotational viscometer to make a viscosity measurement. Each test takes about 3 minutes to set up, run, and clean up after. The viscosity data can vary considerably within a single test, especially for the dressings with particles and chunks; we are not sure which viscosity value to use. Is there an alternative way to do this test that takes less time and involves only one spindle choice?


Since you are testing for consistency, the Texture Analyzer provides a much quicker method. You can choose between two different types of probes: the TA-MP wire mesh probe and the TA43 spherical ball probe. The Texture Analyzer pushes the probe down into the dressing at a defined rate of speed, perhaps 2mm/sec, and measures the load force in grams, which is the dressing’s resistance to being displaced. The load reaches a steady state value within seconds as the probe becomes fully immersed. This is a much simpler test, it’s quicker to perform, the load force value is fairly constant, and the clean up afterwards is easy. You can do everything in less than 1 minute.

Submitted by: Anonymous


CUSTOMER CHALLENGE: We are a manufacturer of pharmaceutical products encapsulated in soft-shell gelatin capsules. It may become necessary for us to produce our own gelatin capsules in the future to accommodate certain formulations. What is meant when the gelatin industry uses the term "Bloom Strength"?

BROOKFIELD ANSWERS: The Gelatin Manufacturers Institute of America has defined a procedure for measuring the strength of a gelatin formulation as follows:

A water solution consisting of 6.67% gelatin (7.50 +/- 0.1g gelatin and 105.0 +/- 0.2g deionized water, melted at 60-65°C) is prepared in a 150 mL, wide-mouth, glass bottle, which is then placed in a chilled water bath and held at 10+/- 0.1°C for 17 +/- 1 hours. After chilling, the rigidity of the gel is measured as the force, in grams, required to impress a standard 0.500 +/- 0.001 inch diameter cylindrical plunger (Bloom probe) to a depth of 4 millimeters into the surface of the gel. This force measurement is referred to as the gel strength, or Bloom rating, of the gelatin. The greater the force required, the higher the strength of the gel. Commercial gelatins range from 50 to 300 Bloom grams.

One type of instrument that measures Bloom strength is the Brookfield CT3 Texture Analyzer. After the Bloom probe makes contact with the gelatin, the instrument automatically moves the probe a distance of 4mm into the material at a rate of 0.5mm/sec. The measured force increases until reaching a peak value at the final depth of 4mm. This measured force value on the instrument display is the Bloom strength.

Submitted by: anonymous


CUSTOMER CHALLENGE: When should I use a single stroke compression test vs. the double stroke characteristic of Texture Profile Analysis (TPA)?

BROOKFIELD ANSWERS: Most materials are tested successfully with a single stroke compression test. The maximum force (also known as "peak load") measured by the probe during the compression cycle is the important parameter. Examples include:

a) the penetration force measured by a Magness Taylor punch probe when it ruptures the skin of a fresh apple
b) the cohesiveness of a bilayer tablet when sheared by the blade in the guillotine fixture
c) the firmness of yogurt when a ball probe pushes down into a container
d) the hardness of a chewy health bar when cut by a shear blade

TPA is appropriate for materials that try to recover their original shape. Squeezing a bread roll or pressing down on a slice of bread are typical examples. Both will bounce back to some degree after being compressed with a cylinder probe. On the second compression stroke, the probe will travel a greater distance before making contact with the object. The change in shape of the item (the distance that it compresses after the first stroke) is measured and is used in established calculations for "springiness" and "chewiness".

Submitted by: anonymous


CUSTOMER CHALLENGE: Is there a "best practice" for selecting the probe travel speed when performing a texture test?

BROOKFIELD ANSWERS: A practical approach is to consider the application that you simulating with the Texture Analyzer. For example, if the action is squeezing a bread roll in your hand, then a probe speed of 1 to 3 mm per second for the large diameter cylinder probe is a good choice. Another example, like the settling of fruit pieces in a yogurt container, requires a very slow probe rate, perhaps 0.1 mm per second for the ball probe. A third example, like chopping vegetables with a blade, would use a rapid speed such as 10mm per second for the blade or wire probe.

If the objective is to establish a QC test procedure, then any speed may be appropriate. This suggests that trial and error be used to establish a speed that provides repeatable test results. One practical consideration in setting up the QC method is to minimize test time by selecting a probe speed that allows the test to complete in the smallest amount of time possible.

Submitted by: anonymous


CUSTOMER CHALLENGE: Is there a maximum distance that a probe should penetrate an object during a compression test?

BROOKFIELD ANSWERS: Run several tests on the object with a penetration distance that does not exceed half of the item's thickness. For example, a candy bar that is 20mm high, suggests using a penetration distance up to 10mm in order to evalute the filling in the interior of the bar. If the objective is to evaluate only the chocolate coating around the candy bar, then the penetraion distance would be much smaller, perhaps 2mm. It is possible to penetrate the object to more than half of its thickness, but there is a risk that "base effects" from the table supporting the object may influence the load readings.

Submitted by: anonymous


CUSTOMER CHALLENGE: Does the pharmaceutical industry use Texture Analyzers?

BROOKFIELD ANSWERS: There are a variety of established tests to consider. Hardness of tablets and capsules is measured by crushing the object in a compression test. Integrity and strength of the gel capsule shell is evaluated with a tension test. Coatings on tablets can be tested for adhesion. Actuation force to squeeze medical ointments out of tubes is evaluated with an extrusion test. There are special fixtures that have been designed to handle the sample for each of these test methods. The reason for these types of tests is to ensure that consumer expectations are met when handling or consuming the pharmaceutical item.

Submitted by: anonymous


CUSTOMER CHALLENGE: When does it make sense to use a Texture Analyzer instead of a Viscometer?

BROOKFIELD ANSWERS: When investigating the mouth feel of a food item during chewing, the Texture Analyzer is the obvious choice because it can simulate the grinding action of the molar teeth. The same applies to the use of your hands when squeezing a food item, like a hard roll or a piece of fruit. Similarly, poking and cutting a piece of meat, fish or poultry is best evaluated by a Texture Analyzer with shear blade or punch probe. In summary, the nature of the action under evaluation suggests the best tool to perform the test. Viscometers are the logical choice for liquids, Texture Analyzers for solids, and either may be considered for soft-solid materials.

Submitted by: anonymous


CUSTOMER CHALLENGE: How can we analyze the mayonnaise texture?

My questions are related to Mayonnaise, that are:

1. How can we analyze the mayonnaise texture?

2. At what temperature we should measure mayonnaise viscosity through offline Brookfield viscometer? (generally we cool mayonnaise from 29 degree Celsius to 25 Degree Celsius)

3. How can we reduce handling error for Viscosity measurement through Brookfield Viscometer?

BROOKFIELD ANSWERS: Thank you for your inquiry.

Viscosity measurement of mayonnaise has traditionally been accomplished with Brookfield T-Bar spindle and Helipath Stand accessory when using Brookfield viscometer with RV Torque Range. New methods allow for use of vane spindle with Brookfield DV3 Rheometer to measure the yield stress in mayonnaise as well as the viscosity.

Texture measurement of mayonnaise is performed with CT3 Texture Analyzer and choice of various fixtures, depending on the physical property of interest. The TA-STF measures spreadability. The TA-DEC measures extrusion. And the TA-MP measures consistency.

Go to the Brookfield website to see images of the above items: www.brookfieldengineering.com.

CUSTOMER CHALLENGE: When I perform multiple cycle tests, I don't see the same results in stand alone mode that I see when using the software, why?

BROOKFIELD ANSWERS: When running a test consisting of multiple cycles you will get three results in standalone mode. They are peak hardness (highest peak of all cycles), hardness of the last peak, and the standard deviation of all peaks. At this time, the TexturePro CT software only provides the hardness of the first peak and the average of all cycle peaks.

Submitted by: anonymous

CUSTOMER CHALLENGE: We are occasionally asked, what is the safe temperature range for our texture probes?

BROOKFIELD ANSWERS:The answer depends upon which probe. Our plastic probes come in two types of material. They are clear acrylic and black delrin. The temperature range for each probe is as follows:

  • Acrylic Service Temperature – (0F -150F)
  • Delrin Service Temperature – (-40F to 185F)

Submitted by: anonymous

CUSTOMER CHALLENGE: Can the CT3 be connected to a printer or an external computer via the USB or RS232 ports?

BROOKFIELD ANSWERS: No data comes out of either the USB or RS232 port in standalone mode. Data is only available at these ports when running with Texture Pro CT software. We occasionally field related questions whenever customers consider connecting to a PC and writing their own data acquisition software. This is impractical and should be discouraged.

Submitted by: anonymous